Various thermal heads have been proposed for printing devices, such as facsimile machines and video printers. For example, a thermal head described in Patent Literature 1 includes a substrate, an electrode on the substrate, a heating portion connected to the electrode, and a protective layer disposed on the heating portion. The protective layer of the thermal head includes a first layer formed of an inorganic material containing silicon oxide and/or silicon nitride, a second layer formed of sintered perhydropolysilazane, and a third layer formed of an inorganic material containing silicon nitride and/or silicon carbide (see Patent Literature 1).